Engineering Projects

There are various type of emergency light circuits. Every circuit has its own importance and utility. But size, cost and efficiency of the circuit are some of the main feature of interest. A very simple circuit of mini emergency light is given here. In normal daylight or electric light, the LDR offer very low resistance. So the positive voltage is applied to the base of transistor T1, making it reverse biased. Therefore, T1 does not conduct in presence of light. As transistor T2 also is reverse biased it does not…

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The fluorescent tube-light requires additional gear such as the copper ballast and starter for normal operation. These two are required to provide the initial high voltage for ionization and thereafter to limit the current through the tube to safe values. It has been observed that the illumination efficiency of the tube-light when excited by high frequency power source is higher than that when excited at the 50Hz line frequency. Moreover, the power factor and the efficiency of the bulky copper ballasts are poor. Hence, electronic ballasts circuit were developed to…

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The compression and expansion are two important techniques used by audio engineers during recording and reproduction of program material. The compression of dynamic range of program material (records, speech or musical broadcasting) permits maintaining constantly high modulating level while the expansion, when used with the reproduction of compressed material, restores the dynamic range and creates a ‘live’ music. Thus, we are created simple and basic project Expander Compressor Unit Circuit. Circuit Description of Expander Compressor Unit Circuit | Compander Creating these effects is costly and complex, and beyond the scope of amateur…

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